Davison was born in Blackheath, London, the daughter of Charles Davison (of Morpeth, Northumberland) and Margaret Davison (of Longhorsley, Northumberland). She had two sisters, a brother and half-siblings from her father’s first marriage including a half-brother, retired naval captain Henry Jocelyn Davison, who gave evidence at her inquest.

She later attended Kensington High School and won a bursary to Royal Holloway College in 1891 to study literature and modern foreign languages. She took up her place in January 1892, but she was forced to drop out the following year when her father died and her mother could not afford the fees of £30 a term. She then became a private governess before becoming a teacher in Edgbaston and Worthing, raising enough money to study Biology, Chemistry, English Language and Literature at St Hugh’s College, Oxford. She obtained first-class honours in her final exams, though women were not at that time admitted to degrees at Oxford. Davison then began teaching the daughters of the Moorhouse family in Spratton, Northamptonshire.

In 1906, Davison joined the Women’s Social and Political Union (WSPU). Formed in 1903 by Emmeline Pankhurst, the WSPU brought together those who felt strongly that militant, confrontational tactics were needed in order to achieve women’s suffrage. In 1908, Davison left her teaching post to dedicate herself completely to the movement. In the same year she entered the University of London examinations as an external candidate for a degree in Modern Foreign Languages.  She gained a reputation as a militant and violent campaigner. On her own initiative and without WSPU approval, her actions developed from disrupting meetings to stone throwing and arson. She was arrested and imprisoned for various offences nine times, including a violent attack on a man she mistook for the Chancellor of the Exchequer, David Lloyd George. During many of these prison terms she went on hunger strike and was force-fed.

On 2 April 1911, the night of the 1911 census, Davison hid in a cupboard in St Mary Undercroft the chapel of the Palace of Westminster overnight so that on the census form she could legitimately give her place of residence that night as the “House of Commons”. The 1911 census documents that were uncovered state that Emily Wilding Davison was found “hiding in the crypt” in the Houses of Parliament. In 1999 a plaque to commemorate the event was set in place by Tony Benn MP.  In June 1912, near the end of a six-month sentence in Holloway Prison for arson, she reacted to an episode in which she and dozens of fellow suffragettes were force-fed, by throwing herself down a 10 metre iron staircase. Her intention, as she wrote afterwards, was to stop the suffering of everyone else by carrying out this action. As a result she suffered severe head and spinal damage, causing discomfort for the remaining twelve months of her life.

On 4 June 1913, Davison attended the Epsom Derby. As the race was underway, she ran on to the track and attempted to grab the bridle of Anmer, the horse owned by King George V. The horse collided with her and she fell to the ground, where she was trampled by its hoofs as it too fell. Meanwhile, the jockey, Herbert Jones, was thrown but had his foot caught in the stirrup. The horse did a somersault, got up, and resumed running the race, dragging the unconscious Jones before his foot came loose. Bystanders unsuccessfully attempted to revive both Davison and Jones, before they were carried off by ambulances.

Davison’s purpose in attending the Derby is not clear. She had purchased a return rail ticket and a ticket to a suffragette dance later that day, both of which are now in the collection of the Women’s Library in London, which suggests that martyrdom was not her intention. Although it later became clear it was the only type of rail ticket available for purchase, it is noted that she carefully kept the return half in her purse. Further evidence is a postcard she wrote to her sister Laetitia, who lived in France and to whom she was very close, which suggests she was going on holiday a few days after the Derby to visit her sister and her niece.

It is a possibility that she entered the race track in order to attach a flag to Anmer, so that when the horse crossed the finishing line, it would be flying the WSPU flag. According to police reports, two flags were found in her possession. Pathé News captured the incident on film. Film, taken at Tattenham Corner, shows Davison stepping out onto the racecourse just as the leading horses swept by. She was then seen standing in the middle of the racecourse as two more horses passed on the inside of her, and was then knocked to the ground by one of the last few trailing horses, the King’s horse Anmer. The film is unclear, but it is possible that by this point she had taken the banner of the WSPU out from where it was concealed in her clothing, with the intention of attaching it to the horse. Eyewitnesses at the time were divided as to her motivation, with many feeling that she had simply intended to cross the track, believing that all horses had passed. Others reported that she had attempted to pull down the King’s horse. It is sometimes suggested that a few weeks beforehand Emily Davison and other suffragettes were “practising” grabbing horses in the park near her mother’s house in Morpeth and that they drew straws to decide who should be the one to go to Epsom.

Horse racing historian Michael Tanner, in a 2011 TV interview at Epsom, pointed out that, as Emily Davison was standing on the inside of the bend at Tattenham Corner amidst heaving crowds, and with no racetrack commentary as there is today, it would not have been possible to know whether the King’s horse had already gone past. In addition, considering the speeds the horses were going, it would not have been possible for her to identify any particular horse even if she had meant to. This suggests that the fact it was the King’s horse that she collided with was just a coincidence. Tanner later described the story of her “practising” with galloping horses and “drawing straws” as “folklore at best, pure hokum at worst,” emphasising that “by 1913 Davison’s modus operandi was acting alone – no one knew of her plans, in Morpeth or elsewhere.”

The most recent theory is that she intended to throw a Votes for Women sash around the neck of the King’s horse to gain publicity for her cause. A sash apparently found at the scene immediately after the collision was recently purchased at auction by author Barbara Gorna, the closest losing bidder being the Jockey Club, and now hangs in the Houses of Parliament. This theory received support from a 2013 examination of the incident, in which forensic experts examined and correlated footage captured by three different newsreel cameras, and determined that Davison was much closer to the start of the bend than had been previously assumed, and so would have had a much clearer view of the oncoming horses than previously thought. It concluded that Davison, who clearly carried in her hand something that could have been the folded Votes for Women sash as she ducked under a barrier and onto the course, did intend to attach it to the king’s horse, and that there was no question of her deliberately throwing herself under the horse.

However, in his 2013 book The Suffragette Derby, Tanner examined the provenance of this “sash”, which is in fact a scarf, and found it wanting: its original owner, Richard Pittway Burton, was not Epsom’s Clerk of the Course, as claimed, but an East End docker with no racing connection whatsoever. Nor, he argued, could the article in Davison’s hand be safely identified as a scarf in the first place: the evidence was skewed to suit. In a letter to the Racing Post Tanner went on to deplore the reiteration of “several myths” attached to Davison that he had debunked in his book, and expressed deep reservations about the film footage analysis, stressing once more that “from her position wedged tight against the rail, Davison would need to have been on a 20-foot ladder to have seen over the heads of the people to her right and then the leading bunch of nine horses to single out the figure of Anmer hidden behind… she was already ducking under the rail as the first horses passed and had missed two-thirds of the field altogether – which for all she knew may have included Anmer. It was pure chance that she stumbled upon Anmer.”

Davison died four days later in Epsom Cottage Hospital due to a fractured skull and internal injuries caused by the incident. Jones suffered a mild concussion, but allegedly was “haunted by that poor woman’s face” for much longer. In 1928, at the funeral of Emmeline Pankhurst, Jones laid a wreath “to do honour to the memory of Mrs Pankhurst and Miss Emily Davison”. However, Tanner rejects both this and the inference that the Epsom incident contributed to the jockey’s suicide in 1951, having interviewed both of Jones’s children for his book: “Their father killed himself 38 years later following the death of his wife and a loneliness brought on by deafness.”